docs: def install_extras(
      include=ALL_EXTRAS,
      *,
      exclude=EMPTY_SET,
      raise_on_error=False,
      warn_on_error=True
  ):
      """Installs extras.
  
      Installing an extra means registering pretty printers for objects from third
      party libraries and/or enabling integrations with other python programs.
  
      - ``'attrs'`` - automatically pretty prints classes created using the ``attrs`` package.
      - ``'dataclasses'`` - automatically pretty prints classes created using the ``dataclasses``
        module.
      - ``'django'`` - automatically pretty prints Model and QuerySet subclasses defined in your
          Django apps.
      - ``numpy`` - automatically pretty prints numpy scalars with explicit types, and,
        for numpy>=1.14, numpy arrays.
      - ``'requests'`` - automatically pretty prints Requests, Responses, Sessions, etc.
      - ``'ipython'`` - makes prettyprinter the default printer in the IPython shell.
      - ``'python'`` - makes prettyprinter the default printer in the default Python shell.
      - ``'ipython_repr_pretty'`` - automatically prints objects that define a ``_repr_pretty_``
        method to integrate with `IPython.lib.pretty
        <http://ipython.readthedocs.io/en/stable/api/generated/IPython.lib.pretty.html#extending>`_.
  
      :param include: an iterable of strs representing the extras to include.
          All extras are included by default.
      :param exclude: an iterable of strs representing the extras to exclude.
      """  # noqa
      include = set(include)
      exclude = set(exclude)
  
      unexisting_extras = (include | exclude) - ALL_EXTRAS
  
      if unexisting_extras:
          raise ValueError(
              "The following extras don't exist: {}".format(
                  ', '.join(unexisting_extras)
              )
          )
  
      extras_to_install = (ALL_EXTRAS & include) - exclude
  
      for extra in extras_to_install:
          module_name = 'prettyprinter.extras.' + extra
          try:
              extra_module = import_module(module_name)
          except ImportError as e:
              if raise_on_error:
                  raise e
              if warn_on_error:
                  warnings.warn(
                      "Failed to import '{0}' PrettyPrinter extra. "
                      "If you don't need it, call install_extras with "
                      "exclude=['{0}']".format(extra)
                  )
          else:
              try:
                  extra_module.install()
              except Exception as exc:
                  if raise_on_error:
                      raise exc
                  elif warn_on_error:
                      warnings.warn(
                          "Failed to install '{0}' PrettyPrinter extra. "
                          "If you don't need it, call install_extras with "
                          "exclude=['{0}']".format(extra)
                      )